Transglutaminase mediated asprosin oligomerization allows its tissue storage as fibers

Asprosin, the C-terminal furin cleavage product of profibrillin-1, was reported to act as a hormone that circulates at nanomolar levels and is recruited to the liver where it induces G protein-coupled activation of the cAMP-PKA pathway and stimulates rapid glucose release into the circulation. Although derived from profibrillin-1, a multidomain extracellular matrix glycoprotein with a ubiquitous distribution in connective tissues, little is known about the tissue distribution of asprosin. In the current view, asprosin is mainly produced by white adipose tissue from where it is released into the blood in monomeric form. Here, by employing newly generated specific asprosin antibodies we monitored the distribution pattern of asprosin in human and murine connective tissues such as placenta, and muscle. Thereby we detected the presence of asprosin positive extracellular fibers. Further, by screening established cell lines for asprosin synthesis we found that most cells derived from musculoskeletal tissues render asprosin into an oligomerized form. This oligomerization is facilitated by transglutaminase activity and requires an intact fibrillin fiber network for proper linear deposition. Our data suggest a new extracellular storage mechanism of asprosin in oligomerized form which may regulate its cellular bioavailability in tissues.

ISOLATION OF LIVE CELLS FROM DIFFERENT MICE TISSUES UP TO NINE DAYS AFTER DEATH

Some limited reports suggest that cells can survive in the cadavers for much longer than it was previously thought. In our study we explored how time after death, tissue type (muscle, brain and adipose tissue), storage temperature of cadavers (4 °C or at room temperature) and form of tissue storage (stored as cadavers or tissue pieces in phosphate buffered saline) affect the success of harvesting live cells from mice after death. Cells were isolated from dead tissues and grown in standard conditions. Some cells were used for RNA extraction and RT² Profiler™ PCR Array for cell lineage identification was performed to establish which lineages the cells obtained from post mortem tissues belong to. Results of our study showed that viable cells can be regularly isolated from muscle and brain tissue 3 days post mortem and with difficulty up to 6 days post mortem. Viable cells from brain tissue can be isolated up to 9 days post mortem. No cells were isolated from adipose tissue except immediately after death. In all instances viable cells were isolated only when tissues were stored at 4 °C. Tissue storage did not affect cell isolation. Isolated cells were progenitors from different germ layers. Our results show that live cells could be obtained from mouse cadavers several days after death.Key words: mouse; cadaver; stem cells; brain; muscle; adipose tissue IZOLACIJA ŽIVIH CELIC IZ RAZLIČNIH TKIV MIŠI DO DEVET DNI PO SMRTI Izvleček: Nekatere raziskave kažejo, da je preživetje celic v truplih precej daljše, kot je bilo znano do sedaj. V naši raziskavi smo proučevali, kako na uspešnost izolacije živih celic po smrti miši vplivajo različen čas izolacije po smrti, vrsta tkiva (mišično, možgansko in maščobno), temperatura shranjevanja trupel ter oblika shranjenega tkiva (kot koščki tkiv ali kot celi kadavri). Izolacija in gojenje celic iz tkiv mrtvih miši sta potekali pod standardnimi pogoji. Da bi ugotovili, katerim celičnim linijam pripadajo izolirane celice, je bil del celic uporabljen za izolacijo RNK in nadaljno uporabo v sistemu identifikacije izvornih celičnih linij z verižno reakcijo s polimerazo v realnem času. Rezultati naše raziskave so pokazali, da je žive celice mogoče izolirati iz mišičnega in možganskega tkiva 3 dni po smrti, pogojno tudi do 6 dni po smrti. Iz možganskega tkiva je bilo žive celice mogoče izolirati tudi do 9 dni po smrti. Iz maščobnega tkiva je bilo celice mogoče izolirati zgolj takoj po smrti, ne pa tudi v kasnejših časovnih intervalih. V vseh primerih so bile celice izolirane samo v primeru shranjevanja tkiv pri 4°C. Oblika shranjenega tkiva na izolacijo celic ni vplivala. Izolirane celice so pripadale različnim zarodnim plastem. Rezultati raziskave so pokazali, da je žive celice iz mišjih trupel mogoče izolirati tudi več dni po smrti.Ključne besede: miš; truplo; matične celice; možgansko tkivo; mišično tkivo; maščobno tkivo

Early insulin-resistance, T2D and treatment options in childhood

Background T2D (Type 2 Diabetes) represents just the tip of the iceberg of the complex metabolic alterations associated with obesity and other clinical conditions associated to impaired adipose tissue storage. Summary Available data have suggested the presence of a continuous spectrum of metabolic alterations developed in the progression from IR to T2D, most of which are likely preventable through the early characterization of all the multiple risk factors involved. Therefore, the complete characterization of the natural history of the disease and the major modifiable factors represents a milestone in the daily care of young subject at risk for the development of impaired glucose metabolism early in life. This review will focus on the main components defining the risk of IR and T2D in childhood with a specific focus on the main aspects of treatment options available in children and adolescents. Key messages Impaired adipose tissue storage documented in obesity results in a continuous spectrum of metabolic alterations ranging from IR to T2DM. These metabolic alterations are mostly likely preventable through the early characterization of all the multiple risk factors involved. The complete characterization of the disease and of the major modifiable factors represent a milestone in the daily care of young subject at risk for the development of impaired glucose metabolism early in life.

Inconsistencies in fertility preservation for young people with cancer in the UK

ObjectiveTo assess the utilisation of and funding structure for fertility preservation for children diagnosed with cancer in the UK.DesignSurvey of paediatric oncologists/haematologists. Questionnaires were sent electronically with reminder notifications to non-responders.SettingUK Paediatric Oncology Principal Treatment Centres (PTCs).ParticipantsPaediatric oncologists/haematologists with an interest in the effects of treatment on fertility representing the 20 PTCs across the UK.Main outcome measuresReferral practices, sources and length of funding for storage of gametes or gonadal tissue for children diagnosed with cancer in the preceding 12 months.ResultsResponses were received from 18 PTCs (90%) with responses to 98.3% of questions. All centres had referred patients for fertility preservation: ovarian tissue collection/storage 100% (n=18 centres), sperm banking 100% (n=17; one centre was excluded due to the age range of their patients), testicular tissue storage 83% (n=15), mature oocyte collection 35% (n=6; one centre was excluded due to the age range of their patients). All centres with knowledge of their funding source reported sperm cryopreservation was NHS funded. Only 60% (n=9) centres reported the same for mature oocyte storage. Of the centres aware of their funding source, half reported that ovarian and testicular tissue storage was funded by charitable sources; this increased in England compared with the rest of the UK.ConclusionsInequality exists in provision of fertility preservation for children with cancer across the UK. There is lack of formalised government funding to support international guidelines, with resultant geographical variation in care. Centralised funding of fertility preservation for children and young adults is needed alongside establishment of a national advisory panel to support all PTCs.

Fungal microbiomes are determined by host phylogeny and exhibit widespread associations with the bacterial microbiome

Interactions between hosts and their resident microbial communities are a fundamental component of fitness for both agents. Though recent research has highlighted the importance of interactions between animals and their bacterial communities, comparative evidence for fungi is lacking, especially in natural populations. Using data from 49 species, we present novel evidence of strong covariation between fungal and bacterial communities across the host phylogeny, indicative of recruitment by hosts for specific suites of microbes. Using co-occurrence networks, we demonstrate marked variation across host taxonomy in patterns of covariation between bacterial and fungal abundances. Host phylogeny drives differences in the overall richness of bacterial and fungal communities, but the effect of diet on richness was only evident in the mammalian gut microbiome. Sample type, tissue storage and DNA extraction method also affected bacterial and fungal community composition, and future studies would benefit from standardized approaches to sample processing. Collectively these data indicate fungal microbiomes may play a key role in host fitness and suggest an urgent need to study multiple agents of the animal microbiome to accurately determine the strength and ecological significance of host–microbe interactions.

Bovine Satellite Cells Isolated after 2 and 5 Days of Tissue Storage Maintain the Proliferative and Myogenic Capacity Needed for Cultured Meat Production

Cultured meat is an emerging alternative food technology which aims to deliver a more ethical, sustainable, and healthy muscle-tissue-derived food item compared to conventional meat. As start-up companies are rapidly forming and accelerating this technology, many aspects of this multi-faceted science have still not been investigated in academia. In this study, we investigated if bovine satellite cells with the ability to proliferate and undergo myogenic differentiation could be isolated after extended tissue storage, for the purpose of increasing the practicality for cultured meat production. Proliferation of bovine satellite cells isolated on the day of arrival or after 2 and 5 days of tissue storage were analyzed by metabolic and DNA-based assays, while their myogenic characteristics were investigated using RT-qPCR and immunofluorescence. Extended tissue storage up to 5 days did not negatively affect proliferation nor the ability to undergo fusion and create myosin heavy chain-positive myotubes. The expression patterns of myogenic and muscle-specific genes were also not affected after tissue storage. In fact, the data indicated a positive trend in terms of myogenic potential after tissue storage, although it was non-significant. These results suggest that the timeframe of which viable myogenic satellite cells can be isolated and used for cultured meat production can be greatly extended by proper tissue storage.

Effects of processing, storage time, and tissue volume in the retrieval and quality of RNA and the expression level of RNU6

Background: Molecular analyses of tumor RNA expression have become widely used both for research and clinical purposes. Tumoral tissue preservation is a critical step to ensure accuracy of molecular-based diagnostics, for which, formalin-fixed and paraffin-embedded (FFPE) tissues represent a valuable source of clinical samples. MicroRNAs are ideal biomarkers in FFPE-tissues, in whose expression evaluation RNU6 is one of the genes used as a normalizer. Our aim was to determine, in FFPE tissue samples, the effects of length of storage and corresponding volume of each studied sample, on the RNA retrieval, quality and concentration, as well as their correlation to the expression level of RNU6. Methods: Fifty tissue blocks with a mean length of tissue storage of 30 months (SD=±12.07, 95% CI= 27.4-34.3). were included. Total RNA was isolated, absorbance and concentrations were determined and correlated with length of storage and volume of tissue. RT-qPCR for RNU6 was performed and their Ct results were correlated to the same parameters. Results: There was a direct correlation between the concentration and quality of the obtained RNA, and an inverse correlation between the tissue storage time and the RNA quality. The volume of tissue studied was not correlated with the RNA quality or concentration. The RNA quality and the length of tissue storage directly correlated to the RNU6 expression level, while RNA concentration and the volume of tissue studied did not affect it. Conclusions: There is an association between longer FFPE tissue storage time with lower RNA quality and lower RNU6 expression level.

The Effects of Fasting or Ketogenic Diet on Endurance Exercise Performance and Metabolism in Female Mice

The promotion of ketone body (KB) metabolism via ketosis has been suggested as a strategy to increase exercise performance. However, studies in humans and animals have yielded inconsistent results. The purpose of the current study was to examine the effects of ketosis, achieved via fasting or a short-term ketogenic diet (KD), on endurance exercise performance in female mice. After 8 h of fasting, serum KB significantly increased and serum glucose significantly decreased in fasted compared to fed mice. When subjected to an endurance exercise capacity (EEC) test on a motorized treadmill, both fed and fasted mice showed similar EEC performance. A 5-week KD (90% calories from fat) significantly increased serum KB but did not increase EEC times compared to chow-fed mice. KD mice gained significantly more weight than chow-fed mice and had greater adipose tissue mass. Biochemical tissue analysis showed that KD led to significant increases in triglyceride content in the heart and liver and significant decreases in glycogen content in the muscle and liver. Furthermore, KD downregulated genes involved in glucose and KB oxidation and upregulated genes involved in lipid metabolism in the heart. These findings suggest that a short-term KD is not an effective strategy to enhance exercise performance and may lead to increased adiposity, abnormal endogenous tissue storage, and cardiometabolic remodeling.

Early postoperative infection following lamellar keratoplasty: a review

With the growing popularity of lamellar keratoplasty for selective replacement of diseased corneal tissue, it is important to understand the risk of developing an infection after the procedure. Although lesser than that postpenetrating keratoplasty, the reports on post lamellar keratoplasty infectious keratitis are not negligible. Trends of acute infections arising within 2 months of surgery are a subject of interest. Most of these infections are reported post Descemet’s stripping endothelial keratoplasty with a preponderance of Candida species. A donor to host transmission of infection is not uncommon. Among the Candida cases, about 80% seem to occur due to a donor to host transmission. Infections presenting as or progressing to endophthalmitis lead to a poor visual outcome. Strict aseptic measures and protocols during corneal tissue harvesting, tissue processing, tissue storage and surgery are essential to prevent occurrence of these infections. After the infection has occurred, determining the aetiology and drug susceptibility through microbiological testing is vital. This helps to guide treatment protocols and hence determines final outcome of these cases. Most cases require some form of surgical management for resolution of infection, most often a graft removal and therapeutic keratoplasty. Secondary surgical interventions are performed to restore graft clarity and achieve a good final visual outcome.